In prior art automatic coating and painting systems, small parts and components are placed in a basket and the basket is coupled to a machine which dips the basket one or more times in a reservoir of paint or other coating material. The basket is then withdrawn from the reservoir and spun rapidly to remove any excess coating material from the parts.
This prior art coating process is effective, but has several severe limitations. The reservoir must contain a large amount of coating material and the coating material in the reservoir can become contaminated after a coating cycle from contaminants on the parts being coated. This degrades the quality of subsequent coating runs unless the coating material is changed. In practice, the coating material in the reservoir is replaced frequently to ensure against contamination and resultant poor quality parts coating. This results in usage of large amounts of coating material, frequent machine down time and a relatively large coating cost per part produced.
Another problem with prior art coating machines is that coatings are applied as a relatively thick single layer. If fast drying coating materials are used, parts in contact with each other adhere together as the coating partially dries, resulting in imperfections on finished parts. Prior art coating machines thus cannot readily use coating materials which could dry appreciably before parts were removed from the coating machine and spread on drying tables.
Additional problems of prior art coating machines are difficult loading, unloading and cleaning procedures.
It is therefore highly desirable to provide an improved parts coating apparatus and method for the high volume coating of small parts. It is also highly desirable to provide an improved parts coating apparatus and method for spray coating parts using both conventional and fast drying coating materials. It is also highly desirable to provide an improved parts coating apparatus wherein the excess coating material can be automatically recycled through a filtering system back to the reservoir containing the coating material.
It is yet also highly desirable to provide an improved parts coating apparatus in which the parts can be coated under an inert gas atmosphere.
It is yet also highly desirable to provide an improved parts coating apparatus which centrifugally removes excess coating material and which has an improved locating mechanism which stops the spinnning basket of parts being coated in a specific position from which the basket can be easily withdrawn from the apparatus.
It is still further highly desirable to provide an improved parts coating apparatus which has all of the above features.
Finally it is highly desirable to provide a method for coating parts by loading parts into a basket, placing the basket in a coating compartment, spraying the parts with a coating material while the basket is in the coating compartment, agitating the parts in the basket while the basket is in the coating compartment, removing the basket from the coating compartment, and unloading the parts from the basket and an apparatus for performing the method.